Minimal functionality implemented

Minimal functionality implemented

src/main.rs

@@ -0,0 +1,176 @@
+#[macro_use]
+extern crate ini;
+
+use std::thread;
+use std::time::Duration;
+use std::process::Command;
+
+/// Rule description structure
+pub struct Rule {
+    /// Monitored service name
+    pub service: String,
+    /// Monitored URI
+    pub address: String,
+    /// E-mail address for messages
+    pub email: String,
+    /// This command will be executed on state change
+    pub command: String,
+    /// Last state
+    pub last_state: bool,
+}
+
+/// Checks service availability
+///
+/// # Arguments
+///
+/// * `uri` - Service URI to be checked
+///
+/// # Example
+///
+/// ```
+/// if if check("https://somesite.local/api/v1/".to_string()).await {
+///     println!("ok");
+/// } else {
+///     println!("uh-oh... something wrong!");
+/// }
+/// ```
+async fn check(uri: String) -> bool {
+    if let Err(_e) = reqwest::get(uri).await {
+        return false;
+    } else {
+        return true;
+    }
+}
+
+/// Output to console only in debug version
+///
+/// # Arguments
+///
+/// * `text` - Message text
+///
+/// # Example
+///
+/// ```
+/// debug_log("Debug version started".to_string());
+/// ```
+fn debug_log(text: String) {
+    if cfg!(debug_assertions) {
+        println!("{}", text);
+    }
+}
+
+/// Execute shell command
+///
+/// In linux sh command interpreter will be called.
+/// In Windows PowerShell command interpreter will be called.
+///
+/// # Arguments
+///
+/// * `command` - Command to be executed
+///
+/// # Example
+///
+/// ```
+/// execute("gedit".to_string());
+/// ```
+fn execute(command: String) {
+    debug_log(format!("execute {}", command));
+
+    let output = if cfg!(target_os = "windows") {
+        Command::new("powershell")
+                .args(["-NoLogo", "-NonInteractive", "-Command",  &command])
+                .output()
+                .expect("failed to execute process")
+    } else {
+        Command::new("sh")
+                .arg("-c")
+                .arg(&command)
+                .output()
+                .expect("failed to execute process")
+    };
+
+    let result = output.stdout;
+    debug_log(format!("{:?}", result));
+}
+
+fn main() {
+    let cfg_file = if cfg!(windows) {
+        "cai-watchdog.cfg"
+    } else {
+        "/etc/cai-watchdog.cfg"
+    };
+
+    let cfg = ini!(cfg_file);
+
+    let check_interval = cfg["main"]["check_interval"].clone().unwrap().parse::<u64>().unwrap();
+    let rules_count    = cfg["main"]["rules_count"].clone().unwrap().parse::<u8>().unwrap();
+
+    let mut tasks = vec![];
+
+    for i in 1..rules_count + 1 {
+        let service = cfg[&format!("{}{}", "rule", i)]["service"].clone().unwrap();
+        let address = cfg[&format!("{}{}", "rule", i)]["address"].clone().unwrap();
+        let email   = cfg[&format!("{}{}", "rule", i)]["email"].clone().unwrap();
+        let command = cfg[&format!("{}{}", "rule", i)]["command"].clone().unwrap();
+
+        debug_log(format!("rule {}", i));
+        debug_log(format!("service {}", service));
+        debug_log(format!("address {}", address));
+        debug_log(format!("email {}", email));
+        debug_log(format!("command {}", command));
+
+        tasks.push(
+            Rule{
+                service:    cfg[&format!("{}{}", "rule", i)]["service"].clone().unwrap().to_string(),
+                address:    cfg[&format!("{}{}", "rule", i)]["address"].clone().unwrap().to_string(),
+                email:      cfg[&format!("{}{}", "rule", i)]["email"].clone().unwrap().to_string(),
+                command:    cfg[&format!("{}{}", "rule", i)]["command"].clone().unwrap().to_string(),
+                last_state: false,
+            }
+        );
+    }
+
+    loop {
+        for i in 0..tasks.len() {
+            let rt = tokio::runtime::Runtime::new().unwrap();
+            rt.block_on(async {
+                if check(tasks[i].address.clone()).await {
+                    if tasks[i].last_state != true {
+                        debug_log(format!("{} state changed to true", tasks[i].address));
+
+                        let shell_cmd = tasks[i].command.to_string()
+                            .replace("<email>", &tasks[i].email)
+                            .replace("<header>", &format!("\"Service {} ({}) online\"", tasks[i].service, tasks[i].address))
+                            .replace("<message>", &format!("\"Service {} ({}) is now online\"", tasks[i].service, tasks[i].address));
+
+                        debug_log(format!("execute {}", shell_cmd));
+
+                        execute(shell_cmd);
+                    }
+
+                    debug_log(format!("{} check is ok", tasks[i].address));
+
+                    tasks[i].last_state = true
+                } else {
+                    if tasks[i].last_state != false {
+                        debug_log(format!("{} state changed to false", tasks[i].address));
+
+                        let shell_cmd = tasks[i].command.to_string()
+                            .replace("<email>", &tasks[i].email)
+                            .replace("<header>", &format!("\"Service {} ({}) offline\"", tasks[i].service, tasks[i].address))
+                            .replace("<message>", &format!("\"Service {} ({}) is now offline\"", tasks[i].service, tasks[i].address));
+
+                        debug_log(format!("execute {}", shell_cmd));
+                        execute(shell_cmd);
+                    }
+
+                    debug_log(format!("{} check failed", tasks[i].address));
+
+                    tasks[i].last_state = false
+                }
+            });
+        }
+
+        thread::sleep(Duration::from_millis(check_interval));
+    }
+}